According to this blog post:
"...High-resolution content can be provided side-by-side with the originals. The “@2x” version will be loaded automatically when needed by the QML Image element..."
I have a QtQuick 2.1 project with two sets of images in my QRC resource file.
Example: image.png and email@example.com
Qt always selects the Low-resolution image (image.png), no matter if I'm on a retina device or not.
Note: The image files are stored in a QRC resource file.